Automatic electric-circuit make and break device



Nov. 5, 1929. I J. SHANNON ET AL 1,734,233

AUTOMAT IC ELECTRIO CIRCUIT MAKE AND BREAK DEVICE Filed May 9, 1927 lnventa r6 Hal/7y 6/747/770; tfa 71 7V J7 7/7/0712 Attorney Patented Nov 5, 1929 UNITED STATES JOHN SHANNGN AND HENRY SHANNON, OF FLORENCE, MASSACHUSETTS AUTOMATIC ELECTRIC-CIRCUIT MAKE AND BREAK DEVICE Application filed May 9, 1927.

pressure is employed.

More specifically the invention has reference to a combination vacuum or pressure control electric switch for such machinery.

Our principal aim is to provide a structure of this kind which is characterized by compactness and convenience in arrangement of parts so located as to produce a dependable and efficient structure for accomplishing the result stated.

The particular details as well as their association and cooperation will become more readily apparent from the following description and drawing.

In the drawing The single figure represents a longitudinal section through a device constructed in accordance with the present invention.

Referring to the drawing in detail it will be seen that the reference character 1 designates a supporting base which is here shown in the form of a channel bar adapted for horizontal disposition. Fastened to one end of this base is a special fitting 2 having astulting box 3 with which the fluid conduct- 5 ing pipe 1 is connected. As intimated, this pipe may conduct either fluid under pressure or fluid under the action of vacuum. Fastoned to the fitting at one end is a metallic expansible and contractible element 5 fre- 0 quently referred to as a bellows. Fitted into one end of this is a cap plate 6 carrying a central screw threaded socket 7 into which the screw threaded end of a reciprocatory rod 8 is passed. A look nut 9 is preferably 5 employed to insure a reliable connection at this point. The opposite end poi tion of this rod extends through a guide opening in a right angular bracket 10. This bracket is bolted to the opposite end portion of the base 11-; 1 and is capable of being reversed. that is Serial No. 189,988.

turned inwardly or outwardly as desired. Disposed on one side of the bracket are nuts 11 forming a shoulder which serves a purpose to be hereinafter described. Also on the extremity of the rod are similar nuts 12 forming another shoulder which in this instance serves as a backing for one end of a coil spring 13 which surrounds the rod between the nut 12 and a washer 1 1 coo crating with the upstanding portion of the racket.

Attention is now directed to a substantially U-shaped upright 15 which is bolted to the central portion of the base. The circuit make and break device is mounted for oscillation between the upper end portions of the arms of this upright and is adapted to rock on a horizontal axis as shown. This device is indicated in its entirety by the reference character 16. It comprises however amounting 17 carrying asuitably shaped container 18 for mercury 19. This container is constructed to accommodate the end portion of the electric current conducting wires 19. The inner ends of these wires extend into the container and are provided with terminals 20 adapted to be bridged by the mercury when the container is tilted to the left or is in a substantially level position. Obviously the mercury bridges the terminals to close the circuit in a well known manner. However, when the container is tilted in a direction from left to right, the mercury flows away from the terminals to break the circuit.

Means is provided on the central portion of the reciprocatory rod for accomplishing the oscillatory action of the make and break device. The means comprises a small cylinder 21 fastened to the intermediate portion of the rod by a headed screw 29.. Incidentally the head of this screw cooperates with an antifriction roller 23 mounted upon the upright. The cylinder is constructed to accommodate a small coiled spring 24- which bears against the headed inner end of a pointed plunger 25. The point of this plunger extends through an opening in the top of the cylinder and engages the central portion of the part 17 of the oscillatory circuit maker and breaker. Normally the plunger is directly beneath the fulcrum point of this device 16. However,

when the rod is reciprocated, a resilient snap conditions.

In the drawing the device is set for operation by vacuum which is active upon the bellows 5 for contracting the same. Obviously, this contraction must take place against the, resisting action of the coiled spring 13. When the vacuum is excessive the rod 8 moves in a direction from right to leftin the drawings, carrying the spring pressed plunger 25 with it, thus as this plunger moves to the left beyond the fulcrum of the device 16, it serves to tilt it in a manner to cause the mercury 19 to flow'away from the terminals 20 to break 4 the electric circuit through the wires 19.

When however the system returns to norm'al and the parts of this device resume their normal position, as shown in the drawings, the device 16 is again righted to assume the level plane, whereupon the mercury again closes the circuit.

As before stated, the device is operable in a pressure system. Assuming that pressure is lntroduced through the pipe 4 against the expansible bellows 5, the action is somewhat the reverse in that the circuit is maintained closed as long as the desired pressure is present in the system, but when the pressure becomes abnormal, then the circuit is broken. In connection with this pressure controlled idea, it is necessary to reverse the position of the sprin by engaging the inner end thereof to the'a oresaid shoulder forming nut 11, and turning the bracket 11 outwardly. Thus the outer end of the spring bears against the bracket, while the inner end bears against the shoulder 11,- and in this way it is necessary for the bellows 5 to overcome the expansive action of the spring From the foregoing description and drawing it will be seen that we have evolved and produced a novel and eflicient structure for automatically controlling an electric circuit or make and break device either by way of vacuum or pressure, according to whichever of these principles is employed in the machinery at band. The gist of the invention, however, is directed to the provision of a device which embodies a suitable base, a fluid actuated bellows device or its equivalent, a fluid line for conducting the vacuum or pressure, an oscillatory switch, and a reciprocatory means controlled by the bellows and active upon the pivotal mounting of the switch for rocking it either one way or the other to open or close the circuit according to the position of the parts. It is believed that when considering this in connection with the drawing, a clear understanding of the construction and operation of the device will be had. Therefore a more lengthy description is thought unnecessary.

Minor changes in shape, size, and rearrangement of parts coming within the scope of the adjoined claims maybe resorted to if desired.

Having thus described the invention, what we claim is 1. In a structure of the class described, a supporting base, an upright on said base, a mercury container embodying electric wire terminals and mercury adapted to bridge said terminals, said container being mounted on an intermediate pivot carried by said upright in order to permit it to oscillate toward and from said base, a reciprocatory rod supported on said base and disposed in parallelism with said container, and spring pressed means carried by said'rod and cooperable withthe intermediate portion of said container for oscillating the latter.

2. In a structure of the class described, a base, a fluid actuated expansible and contractible bellows supported on the base, a guide bracket supported on the base, a rod connected at one end with said bellows-and slidable atits opposite end through said guide, spring means associated with said rod and guide, an upright on said base, a tiltably mounted mercury switch on said upright, and a spring pressured plunger carried on the intermediate portion of the rod for efl'cctiu the tilting motion of said switch.

In testimony whereof we afiix our signatures.

JOHN SHANNON. HENRY SI-IANNON. 

